Simultaneously developing and fixing photographic images



United States Patent 3,252,797 SIMULTANEOUSLY DEVELOPING AND FIXINGPHGTOGRAPHIC IMAGES Dave R. Kazen, Niles, Ill., assignor to ChicagoAerial Industries, inc, Barrington, 1111., a corporation of Deliaware NoDrawing. Filed Nov. 16, 1961, Ser. No. 152,942 11 Claims. (Cl. 96-61)The invention relates to processes for the developmentof silver imagesin photographic silver halide emulsion layers which processes utilizethe simultaneous development and fixing of photographic images and tothe unique compositions of fixing agents.

In the formulation of photographic monobaths, a primary problem ariseswhich has been termed balancing. Balancing may be defined as theadjustment of the concentration and activity of the fixing agentsemployed relative to the concentration and activity of the developingagents. If solution balance is correct, the developing agent is able toinitiate development of latent image centers before fixation proceeds toany appreciable extent. If balance is incorrect and too high aconcentration of fixing agent is employed, the development of the latentimage centers is prevented; because they are destroyed by the fixingprocess prior to development. This destruction of the latent imagecenters by fixing, results in a serious loss of speed of thephotographic emulsion being processed. Furthermore, when the exposurehas been increased to compensate for such a loss of effective emulsionspeed, a fixing agent which acts too rapidly reduces the contrast of theimages formed with the result that negatives produced in such a bath arenot usually considered desirable for photographic printing.

As a result of the exacting requirement due to the balancing problemassociated with monobath processes, there exists a need for a class ofslower fixing rate reagents that would not suffer from low capacity orlow efficiency and at the same time would prove adaptable in processingat various temperatures with known and controllable rates. Monobathprocessing solutions have not been used extensively for thisrequirement, and as the name suggests, monobath photographic processingsolutions combine the developing and fixing solutions into a singlesolution.

The fixing agent compounds which I have found most acceptable in myefforts to overcome the balancing problem consists of chemicalcombinations of water soluble amines, such as the aliphatic amines andderivatives thereof, and an inorganic compound containing an anionsulfite group. It has been found that the mixture of such compoundsunexpectedly combine to produce a chemical synergistic fixing effectthat neither compound is capable of performing separately.

In order to corroborate the relative poor solubility of silver bromidein either the water soluble aliphatic amines or sulfur containing aniongroup compounds and of the solubility of silver bromide in conventionalfixing agents, one may refer to the classic work by Seidell, entitledSolubilities of Inorganic and Metal Organic Compounds, fourth edition(1958). Seidell lists the solubility of silver bromide in solutions ofcertain reagents under optimum conditions as follows:

Since the total solubility of silver halide in a fixing solutiondetermines the maximum capacity of that solution to dissolve the silverhalide, it would appear from the foregoing table that in comparisionwith the conventional fixing agents, the listed aliphatic amine andsodium sulfite would normally prove unacceptable. However, a fixing bathcom-prised of 20% by weight ethylamine and 20% by Weight sodium sulfiteperforms far beyond expectations as a solvent for silver bromide. Infact, it has been found that 0.92 mole per litter of silver bromide maybe placed in solution in such a bath. While this solubility generallyindicates the usefulness of applicants novel fixing agent composition,other considerations such as rate of fixation, the solubility andstability in water of the silver complexes formed during fixing, plusother factors determine the practical usefulness of any fixing bath.

In addition to the novel synergistic fixing effect found when combiningthe aliphatic water soluble amines and/ or its derivatives and aninorganic compound containing an anion group, many additional advantageshave become apparent such as high fixing capacity and high efficiency.As previously suggested, these compositions are of a slower fixing rateclass than the sodium or ammonium thiosulfate fixing agents commonlyemployed. However, unlike other fixing agents used in place of theconventional fixing agents, the fixing agents employed in my inventionhave relatively high capacity and high efficiency. This desirable effectis achieved while at the same time maintaining a controllable rate offixing and correspondingly less active developers are necessary.

Since there are a number of applicable water soluble aliphatic aminecompounds, the combination with the S0 anion compound allows for a widevariation in the pH and ionization constant of the fixing solution. Ithas been found that large molecule aliphatic amines produce sterichindrance, and are less active than the aliphatic amines of smallermolecular size; i.e., N-(Z-hydroxypropyl)-ethylenediamine is less activethan methylam-ine. Hence, a long molecular chain aliphatic aminecombined with an organic sulfite, such as sodium sulfite, may be usedfor fixing at high temperatures, while a shorter chain aliphatic aminecombined with the inorganic sulfite may be used for fixing at lowertemperatures. With the number of water soluble aliphatic aminesapplicable, it is possible to chemically create a fixing agent havingunique charactertistics in order to overcome the monobath balancingproblem.

A principal advantage in the utilization of the combination of thealiphatic amine and an inorganic sulfite is characterized by theextremely high solubility of the formed sliver complexes. Due to theincreased solubility of the silver complexes formed with the fixingreagents utilized in the present invention substantially reducedsludging is encountered in the fixing baths which in turn results in aconsiderable reduction of the maintenance requirement of the bath.Reduced sludging of the process solution is especially important in thecontinuous monobath printing contact processes and in the diffusiontransfer processes where it has hitherto not been possible to put largeamounts of fixer in the solution and still accomplish the desiredresults.

Another advantage realized in the utilization of the invention is thatchemical sulfur staining agents are not formed during the fixingreaction. In addition, the presence of an inorganic acid sulfitecompound in the fixing agents, such as sodium bisulfite or potassiummetabisulfite, will act to prevent oxidation of the developing solutionin the emulsion layer just as they would in an.

acid fixing bath even though the inventive fixing bath solutions aregenerally strongly basic.

chemically combines as a fixer-preservative.

The monobath compositions of the present invention can attain bothhigher densities and higher gammas than heretofore possible in monobathformulas containing thiocyanates or thiosulfates as fixing agents. Forexample, certain compositions of the inventive monobath formulas haveproduced densities in excess of four and gammas in excess of two andone-half. In fact, the inventive monobath compositions, unlike those ofthe prior art, have achieved gamma infinity processing in all ofexperimental emulsions. Futhermore, attainment of these high densitiesand gammas by the inventive monobath compositions have not concomitantlyresulted in a higher fog level or increased processing time.

By way of example of the improvement in gamma and density activity thatmay be achieved using an inventive monobath composition, a comparisonwhich shows the improvement which may be effected is the comparisonbetween the first formula given by way of example in the GoldhammerPatent No. 2,901,350, and the first example in the present application.

The reference formula in the Goldhammer patent employs sodiumthiocyanate and sodium thiosulfate (anhydrous) as the fixing agents andethylene diamine as the alkali constituents. The solution contains atotal of 13.3 grams of developing agent per liter with a total saltcontent of 120 grams per liter. This bath gives a gamma of 0.56 onmedium speed panchromatic film in a processing time of 7 minutes at 68F. The bath prepared in accordance with the present invention usingethylene diamine and sodium bisulfite as both the alkali constituent andthe fixing agent and utilizing the same proportions and amounts of thesame developingagents, has a salt content of only 50 grams per liter andgives with the same film, a gamma of 0.95 and a density range of 2.30 ina processing time of 7 minutes at 68 F. Since the two baths differ onlyin the combination of chemicals used as alkali and fixing agent and inthe resulting salt content and pH, the comparative results show how useof the inventive fixing agents in a bath otherwise identical toGoldhammers results in higher gamma and higher density in a comparabletime.

Monobath formulations utilizing the present invention consists primarilyof a combination fixer-preservative and a developer constituent. Thecombination of an aliphatic amine and an inorganic sulfite compound Theinvention relates primarily to the novel composition of afixer-preservative which utilizes as an aliphatic amine,

singularly or in combination with other aliphatic amines or homologuesthereof to produce a strongly basic soluv tion in combination with aninorganic sulfite compound. The inorganic sulfite compound can be eitheran alkali metal or alkaline earth, such as sodium or calcium.

In general, the following typical primary, secondary, and tertiaryaliphatic amines which are water soluble and are more strongly basic areapplicable providing there are no detrimental side reactions:methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine,triethylamine, n-propylamine, di-n-propylamine, tri-n-propylamine,n-butylamine, n-amylamine, n-hexylaminc, laurylamine, ethylenediamine,trimethylenediamine, tetramethylenediamine, pentamethylenediamine,hexamethylenediamine, ethanolamine, diethanolamine, triethanolamine andallylamine.

The aromatic amines, typified by aniline, are much weaker bases and arenot generally useful.

These aliphatic amines are highly desirable so long as there is noappreciable side reaction, such .as precipitation or reduction in thelevel of development activity. Generally speaking, the higher theionization constant of the aliphatic amine employed the faster theclearing time of the bath.

While most of the examples given employ phenidone (1 phenyl-3-methyl-5pyrazolidone) as a developer in conjunction with hydroquinone as adensity building agent,

it should be understood that the present invention is not limited tothis class of developing agents. Many of the active developing agentssuch as pyrogallol, Metol (monomethyl para-aminophenol sulfate), Amidol(diaminophenol hydrochloride), etc., will also produce useful results,

The following examples illustrate typical monobath formulas:

Example 1 A formula for high contrast processing of medium speedpanchromatic film:

Water (90 F.) ml 750 Sodium bisulfite gr Amidol gr 10 Hydroquinone gr3.3 99.1% ethylene diamine -ml 53.5 0.5% 6-nitrobenzimidazole ml 40Water to make 1.0 liter. pH:10.75. Gamma=0.95. Time=10 minutes at 68 F.Density range:2.3 on medium speed panchromatic film.

Example 2 A typical formula for use with medium speed aerial film andwell adapted for use in saturated web monobath processing systems atdifferent ambient temperatures is characterized by the followingcomposition:

Water (90 F.) ml 750 Sodium sulfite gr 37 Phenidone gr 4 Hydroquinone gr14 Monoethanolamine ml 80 M rcapto succinic acid gr 13 Water to make 1.0liter. pI-I:11.3.

Gamma F. Clearing Time 1. 2 9 minutes. 1. 4 4.5 minutes. 1.6 2minutes.2. 0 1 minute. 2. 5 45 seconds.

Example 3 A typical formula for conventional negative movie film ischaracterized by the following composition:

Water (90 F.) m1 750 Triethanolamine ml 60 Sodium sulfite gr 20 Sodiumbisulfite gr 20 Amidol gr 10 Thiomallic acid gr 5 Water to make 1.0liter. pH=8.4. Gamma=0.7. Time=8 minutes at 75 F. (constant agitation),

Example 4 A rapid processing formula for microfilm adapted for use at avariety of ambient temperature levels is characterized as follows:

Water (90 F.) '1 750 Sodium sulfite gr 37 Hydroquinone gr 14 Phenidonegr 4 Monoethanolamine ml 80 Mercapto succinic acid gr 15 Water to make1.0 liter. pH=11.3.

A formula for high temperature use in substitution of the compositionsuggested in Example 2:

Water (90 F.) mL- 750 Sodium sulfite gr 37 Hydroquinone gr l4 Phenidonegr '4 Monoethanolamine ml 80 Sodium sulfate gr 100 Thiomallic acid gr 13Water to make 1.0 liter.

Time=3 minutes at 90 F. Gamma=1.6 on medium speed aerial film.

Example 6 A formula for the same purpose as formula Number 2 but usingMeto-l (monomethyl para-aminophenol sulfate) in place of .phenidonc (1pheny1-3 methyl-S-pyrazolidone):

Water (90 F.) ml 750 Sodium sulfite gr 37 Metol (monomethylpara-aminophenol sulfate) gr 5 Hydroquinone gr 14 Monoethanolamine ml 80Thiomallic acid gr Water to make 1.0 liter.

Time:5 minutes at 70 F. Gamma=1.5 on medium speed aerial film.

Example 7 A high contrast formula for alternate use with Example 3 inprocessing negative movie film is characterized by the followingcomposition:

Water (90 F.) ml 750 Sodium sulfite gr 37 Hydroquinone gr 14 Phenidone(l phenyl-3-trnethyl-5-pyrazolidone) gr 4 MonoleneN-(2-hydnoxypnopyl)ethylencdiamine gr 100 Thionuanol ml 12.5 Water tomake 1000 cc. pH: 10.8.

Time=4 minutes at 70 F. Gamma=0.93 on negative movie film.

Example 8 A formula in substitution of Example 4 for low temperatureprocessing of microfilm and using pyrogallol as a developing agent inplace of hydroquin one is characterized by the following composition:

Water (90 F.) ml" 750 70% ethylamine ml 50 Thiomallic acid gr 10 Sodiumsulfite gr 37 Pyrogallol gr 14 Phenidone gr 4 Potassium hydroxide gr 16Water to make 1.0 liter.

Time=2 minutes at 65 F. Gamma=2.05 on microfilm.

As pointed out hereinabove, the silver complexes when formed incombination with the inventive fixing agents have high solubilities andthe use of these agents are especially adaptable in diffusion transferprocesses where sludging of the bath is frequently encountered. Aformula using a specific inventive fixing agent composition in adiffusion transfer bath which has an inherently low sludging potentialis characterized by the following composition:

Example 9 Water (90 F.) ..-ml.. 750 Sodium sulfite gr 75 Hydroquinone gr15 Phenidone (1 phenyl-3 methyl-S-py-razolidone) gr 1 Sodium bisulfitegr 5 Monoethanolamine ml Potassium bromide gr 1.5 Water to make 1.0liter.

Since the majority of the amines are liquids or solutions of amines inwater and/ or alcohol, it has been found that the concentrationexcluding water of any of the above formulas may be mixed together inthe proportions stated or in the ratio of proportions stated to formhighly concentrated mixtures having a high storage density. In additionto the high storage density achieved, these mixtures have been found tohave excellent keeping qualities as long as they are kept in airtightcontainers. Combined developing and fixing baths, diffusion transferbaths or fixers can then be prepared conveniently as needed bydissolving the appropriate mixture in an appropriate volume of water.

A fine grain dilutable monobat-h formula using the inventive fixingagents and ideally suited for use with any type of thin film emulsion ischaracterized as follows:

Water F.) ml 500 Catechol gr 62 70% ethylamine ml 200 Sodium sulfite gr31 Potasiurn bromide gr 62 Water to make 1.0 liter.

The above formula has proven useful when diluted with water inproportions varying from A to part of the concentrate with the onlydiiference between the dilution ratios being clearing time. The dilutionratios currently of maximum utility and hence preferred are:

Fi lrn- Dilution Slow speed (thin) 31 parts water to l pant concentrate.

Medium speed (thin) 23 parts water to 1 pant concentrate.

High speed (thin) 16 parts Water to 1 part concentrate.

When subjecting the film to processing at these dilution ratios at 68 F.in the time range from about 20-30 minutes with constant agitation, thegamma will vary between 0.5 and 0.9 depending on the type of emulsion.

While the foregoing examples employing the inventive fixing agents arepresently preferred for the specific uses set forth, it has been foundthat these fixing agents may, in certain instances be employed over avery wide range of proportions of their ingredients and ofconcentrations of the fixing compound in the final working solution.Experimentally, it has been found that the proportion of the aliphaticamine compound to inorganic sulfite compound may vary between the ratiosof 90:1 and 1:20 in Water solutions in which the inventive fixing agentsconcentration varies between 75% and 0.1%. While the above limits onconcentration and ingredient proportions have been experimentallyverified, it has been found that the preferred proportions of thealiphatic amine compound to inorganic sulfite compound vary between 15:1

and 1:3 dependent on emulsion and developer characteristics. The entireabove set forth range of concentrations of the inventive fixing agentsmay vary in use depending primarily on film emulsion characteristics andparticularly film thickness.

It is apparent that many widely different embodiments of this inventionmay be made without departing from the spirit and scope thereof,andtherefore, it is not intended (that the invention be limited exceptas indicated the appended claims.

What is claimed is:

1. A monobath silver halide developing and fixing solution containing asilver halide developing composition and a silver halide fixing solutionwherein the fixing agent consists of a water soluble aliphatic amine andan alkali metal salt of sulphurous acid.

2. A monobath silver halide developing and fixing solution containing asilver halide developing composition and a silver halide fixing solutionwherein the fixing agent consists of a water soluble aliphatic amine, analkali metal salt of sulphurous acid and the pH of said solution beinggreater than 7.

3. A silver halide fixing solution for fixing a silver halide emulsionwherein the fixing agent consists of the combination of a water solublealiphatic amine and an alkali metal inorganic sulfite wherein saidsolution shall be of an alkaline composition.

4. A silver halide fixing solution for fixing a developed silver halideemulsion wherein the fixing agent consists of substantially equal partsby weight of a water soluble aliphatic amine and an alkali metal sulfiteand said solution shall have a pH greater than 7.

5. A silver halide fixing solution for fixing a silver halide emulsionconsisting of ethylene diamine and sodium bisulfite and said solutionshall have an alkaline pH.

6. A monobath silver halide developing and fixing bath containingdiaminophenol hydrochloride, hydroquinone, 6-nitrobenzimadazole, afixing agent consisting of sodium bisulfite and a water soluble amineand the remainder consisting of water to form an alkaline solution.

7. A rapid processing composition for developing and fixing a silverhalide emulsion consisting of sodium sulfite, hydroquinone, l-phenyl 3methyl-S-pyrazolidone,

monoethanolamine, mercapto-succinic acid and the remainder being waterto form an alkaline solution.

8. A diffusion transfer bath having a relatively low sludging potentialcontaining a developing composition of hydroquinone and phenidone and afixing agent consisting of sodium bisulfite and monoethanolamine.

9. A concentrate monobath developing and fixing solution for developinga silver halide film emulsion containing a developing composition ofortho-dihydroxybenzene and a fixing agent consisting of ethylamine andsodium sulfite and said concentrate being subjected to an aqueousdilution depending on the clearing time of the emulsion.

10. A silver halide fixing solution for fixing a silver halide emulsionwherein the fixing agent consists of a Water soluble aliphatic aminecompound, an alkali metal sulfite compound, the chemical proportionaterates of said aliphatic amine compound to said inorganic compound mayvary between 15 :1 and 1:3 respectively and said final solution shall bealkaline.

11. A monobath silver halide developing and fixing solution containingan organic developing agent in admixture with a fixing agent consistingessentially of a water soluble aliphatic amine and an alkali metalsulfite, the total salt content of said solution being attributablesolely to said sulfite.

References Cited by the Examiner UNITED STATES PATENTS 2,875,048 2/1959Haist 96-61 2,901,350 8/1959 Goldhammer 96-61 FOREIGN PATENTS 571,3898/1945 Great Britain.

OTHER REFERENCES Photographic Science and Engineering, vol. 5, No. 4,July-August 1961, pp. 198-203.

J. TRAVIS BROWN, Acting Primary Examiner.

HAROLD N. BURSTEIN, Examiner.

W. C. GILLIS, C. E. DAVIS, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,252,797 May 24, 1966 David R. Kazen It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as corrected below.

Column 2, line 10, for "litter" read liter line 41, for "organic" readinorganic same column 2, line 52, for "sliver" read silver Signed andsealed this 2nd day of January 1968.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

1. A MONOBATH SILVER HALIDE DEVELOPING AND FIXING SOLUTION CONTAINING ASILVER HALIDE DEVELOPING COMPOSITION AND A SILVER HALIDE FIXING SOLUTIONWHEREIN THE FIXING AGENT CONSISTS OF A WATER SOLUBLE ALIPHATIC AMINE ANDAN ALKALI METAL SALT OF SULPHUROUS ACID.